xref: /linux/arch/parisc/mm/init.c (revision ba199dc909a20fe62270ae4e93f263987bb9d119)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/arch/parisc/mm/init.c
4  *
5  *  Copyright (C) 1995	Linus Torvalds
6  *  Copyright 1999 SuSE GmbH
7  *    changed by Philipp Rumpf
8  *  Copyright 1999 Philipp Rumpf (prumpf@tux.org)
9  *  Copyright 2004 Randolph Chung (tausq@debian.org)
10  *  Copyright 2006-2007 Helge Deller (deller@gmx.de)
11  *
12  */
13 
14 
15 #include <linux/module.h>
16 #include <linux/mm.h>
17 #include <linux/memblock.h>
18 #include <linux/gfp.h>
19 #include <linux/delay.h>
20 #include <linux/init.h>
21 #include <linux/initrd.h>
22 #include <linux/swap.h>
23 #include <linux/unistd.h>
24 #include <linux/nodemask.h>	/* for node_online_map */
25 #include <linux/pagemap.h>	/* for release_pages */
26 #include <linux/compat.h>
27 #include <linux/execmem.h>
28 
29 #include <asm/pgalloc.h>
30 #include <asm/tlb.h>
31 #include <asm/pdc_chassis.h>
32 #include <asm/mmzone.h>
33 #include <asm/sections.h>
34 #include <asm/msgbuf.h>
35 #include <asm/sparsemem.h>
36 #include <asm/asm-offsets.h>
37 #include <asm/shmbuf.h>
38 
39 extern int  data_start;
40 extern void parisc_kernel_start(void);	/* Kernel entry point in head.S */
41 
42 #if CONFIG_PGTABLE_LEVELS == 3
43 pmd_t pmd0[PTRS_PER_PMD] __section(".data..vm0.pmd") __attribute__ ((aligned(PAGE_SIZE)));
44 #endif
45 
46 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".data..vm0.pgd") __attribute__ ((aligned(PAGE_SIZE)));
47 pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __section(".data..vm0.pte") __attribute__ ((aligned(PAGE_SIZE)));
48 
49 static struct resource data_resource = {
50 	.name	= "Kernel data",
51 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
52 };
53 
54 static struct resource code_resource = {
55 	.name	= "Kernel code",
56 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
57 };
58 
59 static struct resource pdcdata_resource = {
60 	.name	= "PDC data (Page Zero)",
61 	.start	= 0,
62 	.end	= 0x9ff,
63 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
64 };
65 
66 static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __ro_after_init;
67 
68 /* The following array is initialized from the firmware specific
69  * information retrieved in kernel/inventory.c.
70  */
71 
72 physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata;
73 int npmem_ranges __initdata;
74 
75 #ifdef CONFIG_64BIT
76 #define MAX_MEM         (1UL << MAX_PHYSMEM_BITS)
77 #else /* !CONFIG_64BIT */
78 #define MAX_MEM         (3584U*1024U*1024U)
79 #endif /* !CONFIG_64BIT */
80 
81 static unsigned long mem_limit __read_mostly = MAX_MEM;
82 
83 static void __init mem_limit_func(void)
84 {
85 	char *cp, *end;
86 	unsigned long limit;
87 
88 	/* We need this before __setup() functions are called */
89 
90 	limit = MAX_MEM;
91 	for (cp = boot_command_line; *cp; ) {
92 		if (memcmp(cp, "mem=", 4) == 0) {
93 			cp += 4;
94 			limit = memparse(cp, &end);
95 			if (end != cp)
96 				break;
97 			cp = end;
98 		} else {
99 			while (*cp != ' ' && *cp)
100 				++cp;
101 			while (*cp == ' ')
102 				++cp;
103 		}
104 	}
105 
106 	if (limit < mem_limit)
107 		mem_limit = limit;
108 }
109 
110 #define MAX_GAP (0x40000000UL >> PAGE_SHIFT)
111 
112 static void __init setup_bootmem(void)
113 {
114 	unsigned long mem_max;
115 #ifndef CONFIG_SPARSEMEM
116 	physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1];
117 	int npmem_holes;
118 #endif
119 	int i, sysram_resource_count;
120 
121 	disable_sr_hashing(); /* Turn off space register hashing */
122 
123 	/*
124 	 * Sort the ranges. Since the number of ranges is typically
125 	 * small, and performance is not an issue here, just do
126 	 * a simple insertion sort.
127 	 */
128 
129 	for (i = 1; i < npmem_ranges; i++) {
130 		int j;
131 
132 		for (j = i; j > 0; j--) {
133 			if (pmem_ranges[j-1].start_pfn <
134 			    pmem_ranges[j].start_pfn) {
135 
136 				break;
137 			}
138 			swap(pmem_ranges[j-1], pmem_ranges[j]);
139 		}
140 	}
141 
142 #ifndef CONFIG_SPARSEMEM
143 	/*
144 	 * Throw out ranges that are too far apart (controlled by
145 	 * MAX_GAP).
146 	 */
147 
148 	for (i = 1; i < npmem_ranges; i++) {
149 		if (pmem_ranges[i].start_pfn -
150 			(pmem_ranges[i-1].start_pfn +
151 			 pmem_ranges[i-1].pages) > MAX_GAP) {
152 			npmem_ranges = i;
153 			printk("Large gap in memory detected (%ld pages). "
154 			       "Consider turning on CONFIG_SPARSEMEM\n",
155 			       pmem_ranges[i].start_pfn -
156 			       (pmem_ranges[i-1].start_pfn +
157 			        pmem_ranges[i-1].pages));
158 			break;
159 		}
160 	}
161 #endif
162 
163 	/* Print the memory ranges */
164 	pr_info("Memory Ranges:\n");
165 
166 	for (i = 0; i < npmem_ranges; i++) {
167 		struct resource *res = &sysram_resources[i];
168 		unsigned long start;
169 		unsigned long size;
170 
171 		size = (pmem_ranges[i].pages << PAGE_SHIFT);
172 		start = (pmem_ranges[i].start_pfn << PAGE_SHIFT);
173 		pr_info("%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n",
174 			i, start, start + (size - 1), size >> 20);
175 
176 		/* request memory resource */
177 		res->name = "System RAM";
178 		res->start = start;
179 		res->end = start + size - 1;
180 		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
181 		request_resource(&iomem_resource, res);
182 	}
183 
184 	sysram_resource_count = npmem_ranges;
185 
186 	/*
187 	 * For 32 bit kernels we limit the amount of memory we can
188 	 * support, in order to preserve enough kernel address space
189 	 * for other purposes. For 64 bit kernels we don't normally
190 	 * limit the memory, but this mechanism can be used to
191 	 * artificially limit the amount of memory (and it is written
192 	 * to work with multiple memory ranges).
193 	 */
194 
195 	mem_limit_func();       /* check for "mem=" argument */
196 
197 	mem_max = 0;
198 	for (i = 0; i < npmem_ranges; i++) {
199 		unsigned long rsize;
200 
201 		rsize = pmem_ranges[i].pages << PAGE_SHIFT;
202 		if ((mem_max + rsize) > mem_limit) {
203 			printk(KERN_WARNING "Memory truncated to %ld MB\n", mem_limit >> 20);
204 			if (mem_max == mem_limit)
205 				npmem_ranges = i;
206 			else {
207 				pmem_ranges[i].pages =   (mem_limit >> PAGE_SHIFT)
208 						       - (mem_max >> PAGE_SHIFT);
209 				npmem_ranges = i + 1;
210 				mem_max = mem_limit;
211 			}
212 			break;
213 		}
214 		mem_max += rsize;
215 	}
216 
217 	printk(KERN_INFO "Total Memory: %ld MB\n",mem_max >> 20);
218 
219 #ifndef CONFIG_SPARSEMEM
220 	/* Merge the ranges, keeping track of the holes */
221 	{
222 		unsigned long end_pfn;
223 		unsigned long hole_pages;
224 
225 		npmem_holes = 0;
226 		end_pfn = pmem_ranges[0].start_pfn + pmem_ranges[0].pages;
227 		for (i = 1; i < npmem_ranges; i++) {
228 
229 			hole_pages = pmem_ranges[i].start_pfn - end_pfn;
230 			if (hole_pages) {
231 				pmem_holes[npmem_holes].start_pfn = end_pfn;
232 				pmem_holes[npmem_holes++].pages = hole_pages;
233 				end_pfn += hole_pages;
234 			}
235 			end_pfn += pmem_ranges[i].pages;
236 		}
237 
238 		pmem_ranges[0].pages = end_pfn - pmem_ranges[0].start_pfn;
239 		npmem_ranges = 1;
240 	}
241 #endif
242 
243 	/*
244 	 * Initialize and free the full range of memory in each range.
245 	 */
246 
247 	max_pfn = 0;
248 	for (i = 0; i < npmem_ranges; i++) {
249 		unsigned long start_pfn;
250 		unsigned long npages;
251 		unsigned long start;
252 		unsigned long size;
253 
254 		start_pfn = pmem_ranges[i].start_pfn;
255 		npages = pmem_ranges[i].pages;
256 
257 		start = start_pfn << PAGE_SHIFT;
258 		size = npages << PAGE_SHIFT;
259 
260 		/* add system RAM memblock */
261 		memblock_add(start, size);
262 
263 		if ((start_pfn + npages) > max_pfn)
264 			max_pfn = start_pfn + npages;
265 	}
266 
267 	/*
268 	 * We can't use memblock top-down allocations because we only
269 	 * created the initial mapping up to KERNEL_INITIAL_SIZE in
270 	 * the assembly bootup code.
271 	 */
272 	memblock_set_bottom_up(true);
273 
274 	/* IOMMU is always used to access "high mem" on those boxes
275 	 * that can support enough mem that a PCI device couldn't
276 	 * directly DMA to any physical addresses.
277 	 * ISA DMA support will need to revisit this.
278 	 */
279 	max_low_pfn = max_pfn;
280 
281 	/* reserve PAGE0 pdc memory, kernel text/data/bss & bootmap */
282 
283 #define PDC_CONSOLE_IO_IODC_SIZE 32768
284 
285 	memblock_reserve(0UL, (unsigned long)(PAGE0->mem_free +
286 				PDC_CONSOLE_IO_IODC_SIZE));
287 	memblock_reserve(__pa(KERNEL_BINARY_TEXT_START),
288 			(unsigned long)(_end - KERNEL_BINARY_TEXT_START));
289 
290 #ifndef CONFIG_SPARSEMEM
291 
292 	/* reserve the holes */
293 
294 	for (i = 0; i < npmem_holes; i++) {
295 		memblock_reserve((pmem_holes[i].start_pfn << PAGE_SHIFT),
296 				(pmem_holes[i].pages << PAGE_SHIFT));
297 	}
298 #endif
299 
300 #ifdef CONFIG_BLK_DEV_INITRD
301 	if (initrd_start) {
302 		printk(KERN_INFO "initrd: %08lx-%08lx\n", initrd_start, initrd_end);
303 		if (__pa(initrd_start) < mem_max) {
304 			unsigned long initrd_reserve;
305 
306 			if (__pa(initrd_end) > mem_max) {
307 				initrd_reserve = mem_max - __pa(initrd_start);
308 			} else {
309 				initrd_reserve = initrd_end - initrd_start;
310 			}
311 			initrd_below_start_ok = 1;
312 			printk(KERN_INFO "initrd: reserving %08lx-%08lx (mem_max %08lx)\n", __pa(initrd_start), __pa(initrd_start) + initrd_reserve, mem_max);
313 
314 			memblock_reserve(__pa(initrd_start), initrd_reserve);
315 		}
316 	}
317 #endif
318 
319 	data_resource.start =  virt_to_phys(&data_start);
320 	data_resource.end = virt_to_phys(_end) - 1;
321 	code_resource.start = virt_to_phys(_text);
322 	code_resource.end = virt_to_phys(&data_start)-1;
323 
324 	/* We don't know which region the kernel will be in, so try
325 	 * all of them.
326 	 */
327 	for (i = 0; i < sysram_resource_count; i++) {
328 		struct resource *res = &sysram_resources[i];
329 		request_resource(res, &code_resource);
330 		request_resource(res, &data_resource);
331 	}
332 	request_resource(&sysram_resources[0], &pdcdata_resource);
333 
334 	/* Initialize Page Deallocation Table (PDT) and check for bad memory. */
335 	pdc_pdt_init();
336 
337 	memblock_allow_resize();
338 	memblock_dump_all();
339 }
340 
341 static bool kernel_set_to_readonly;
342 
343 static void __ref map_pages(unsigned long start_vaddr,
344 			    unsigned long start_paddr, unsigned long size,
345 			    pgprot_t pgprot, int force)
346 {
347 	pmd_t *pmd;
348 	pte_t *pg_table;
349 	unsigned long end_paddr;
350 	unsigned long start_pmd;
351 	unsigned long start_pte;
352 	unsigned long tmp1;
353 	unsigned long tmp2;
354 	unsigned long address;
355 	unsigned long vaddr;
356 	unsigned long ro_start;
357 	unsigned long ro_end;
358 	unsigned long kernel_start, kernel_end;
359 
360 	ro_start = __pa((unsigned long)_text);
361 	ro_end   = __pa((unsigned long)&data_start);
362 	kernel_start = __pa((unsigned long)&__init_begin);
363 	kernel_end  = __pa((unsigned long)&_end);
364 
365 	end_paddr = start_paddr + size;
366 
367 	/* for 2-level configuration PTRS_PER_PMD is 0 so start_pmd will be 0 */
368 	start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));
369 	start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
370 
371 	address = start_paddr;
372 	vaddr = start_vaddr;
373 	while (address < end_paddr) {
374 		pgd_t *pgd = pgd_offset_k(vaddr);
375 		p4d_t *p4d = p4d_offset(pgd, vaddr);
376 		pud_t *pud = pud_offset(p4d, vaddr);
377 
378 #if CONFIG_PGTABLE_LEVELS == 3
379 		if (pud_none(*pud)) {
380 			pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER,
381 					     PAGE_SIZE << PMD_TABLE_ORDER);
382 			if (!pmd)
383 				panic("pmd allocation failed.\n");
384 			pud_populate(NULL, pud, pmd);
385 		}
386 #endif
387 
388 		pmd = pmd_offset(pud, vaddr);
389 		for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++, pmd++) {
390 			if (pmd_none(*pmd)) {
391 				pg_table = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
392 				if (!pg_table)
393 					panic("page table allocation failed\n");
394 				pmd_populate_kernel(NULL, pmd, pg_table);
395 			}
396 
397 			pg_table = pte_offset_kernel(pmd, vaddr);
398 			for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {
399 				pte_t pte;
400 				pgprot_t prot;
401 				bool huge = false;
402 
403 				if (force) {
404 					prot = pgprot;
405 				} else if (address < kernel_start || address >= kernel_end) {
406 					/* outside kernel memory */
407 					prot = PAGE_KERNEL;
408 				} else if (!kernel_set_to_readonly) {
409 					/* still initializing, allow writing to RO memory */
410 					prot = PAGE_KERNEL_RWX;
411 					huge = true;
412 				} else if (address >= ro_start) {
413 					/* Code (ro) and Data areas */
414 					prot = (address < ro_end) ?
415 						PAGE_KERNEL_EXEC : PAGE_KERNEL;
416 					huge = true;
417 				} else {
418 					prot = PAGE_KERNEL;
419 				}
420 
421 				pte = __mk_pte(address, prot);
422 				if (huge)
423 					pte = pte_mkhuge(pte);
424 
425 				if (address >= end_paddr)
426 					break;
427 
428 				set_pte(pg_table, pte);
429 
430 				address += PAGE_SIZE;
431 				vaddr += PAGE_SIZE;
432 			}
433 			start_pte = 0;
434 
435 			if (address >= end_paddr)
436 			    break;
437 		}
438 		start_pmd = 0;
439 	}
440 }
441 
442 void __init set_kernel_text_rw(int enable_read_write)
443 {
444 	unsigned long start = (unsigned long) __init_begin;
445 	unsigned long end   = (unsigned long) &data_start;
446 
447 	map_pages(start, __pa(start), end-start,
448 		PAGE_KERNEL_RWX, enable_read_write ? 1:0);
449 
450 	/* force the kernel to see the new page table entries */
451 	flush_cache_all();
452 	flush_tlb_all();
453 }
454 
455 void free_initmem(void)
456 {
457 	unsigned long init_begin = (unsigned long)__init_begin;
458 	unsigned long init_end = (unsigned long)__init_end;
459 	unsigned long kernel_end  = (unsigned long)&_end;
460 
461 	/* Remap kernel text and data, but do not touch init section yet. */
462 	kernel_set_to_readonly = true;
463 	map_pages(init_end, __pa(init_end), kernel_end - init_end,
464 		  PAGE_KERNEL, 0);
465 
466 	/* The init text pages are marked R-X.  We have to
467 	 * flush the icache and mark them RW-
468 	 *
469 	 * Do a dummy remap of the data section first (the data
470 	 * section is already PAGE_KERNEL) to pull in the TLB entries
471 	 * for map_kernel */
472 	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
473 		  PAGE_KERNEL_RWX, 1);
474 	/* now remap at PAGE_KERNEL since the TLB is pre-primed to execute
475 	 * map_pages */
476 	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
477 		  PAGE_KERNEL, 1);
478 
479 	/* force the kernel to see the new TLB entries */
480 	__flush_tlb_range(0, init_begin, kernel_end);
481 
482 	/* finally dump all the instructions which were cached, since the
483 	 * pages are no-longer executable */
484 	flush_icache_range(init_begin, init_end);
485 
486 	free_initmem_default(POISON_FREE_INITMEM);
487 
488 	/* set up a new led state on systems shipped LED State panel */
489 	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_BCOMPLETE);
490 }
491 
492 
493 #ifdef CONFIG_STRICT_KERNEL_RWX
494 void mark_rodata_ro(void)
495 {
496 	/* rodata memory was already mapped with KERNEL_RO access rights by
497            pagetable_init() and map_pages(). No need to do additional stuff here */
498 	unsigned long roai_size = __end_ro_after_init - __start_ro_after_init;
499 
500 	pr_info("Write protected read-only-after-init data: %luk\n", roai_size >> 10);
501 }
502 #endif
503 
504 
505 /*
506  * Just an arbitrary offset to serve as a "hole" between mapping areas
507  * (between top of physical memory and a potential pcxl dma mapping
508  * area, and below the vmalloc mapping area).
509  *
510  * The current 32K value just means that there will be a 32K "hole"
511  * between mapping areas. That means that  any out-of-bounds memory
512  * accesses will hopefully be caught. The vmalloc() routines leaves
513  * a hole of 4kB between each vmalloced area for the same reason.
514  */
515 
516  /* Leave room for gateway page expansion */
517 #if KERNEL_MAP_START < GATEWAY_PAGE_SIZE
518 #error KERNEL_MAP_START is in gateway reserved region
519 #endif
520 #define MAP_START (KERNEL_MAP_START)
521 
522 #define VM_MAP_OFFSET  (32*1024)
523 #define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \
524 				     & ~(VM_MAP_OFFSET-1)))
525 
526 void *parisc_vmalloc_start __ro_after_init;
527 EXPORT_SYMBOL(parisc_vmalloc_start);
528 
529 void __init mem_init(void)
530 {
531 	/* Do sanity checks on IPC (compat) structures */
532 	BUILD_BUG_ON(sizeof(struct ipc64_perm) != 48);
533 #ifndef CONFIG_64BIT
534 	BUILD_BUG_ON(sizeof(struct semid64_ds) != 80);
535 	BUILD_BUG_ON(sizeof(struct msqid64_ds) != 104);
536 	BUILD_BUG_ON(sizeof(struct shmid64_ds) != 104);
537 #endif
538 #ifdef CONFIG_COMPAT
539 	BUILD_BUG_ON(sizeof(struct compat_ipc64_perm) != sizeof(struct ipc64_perm));
540 	BUILD_BUG_ON(sizeof(struct compat_semid64_ds) != 80);
541 	BUILD_BUG_ON(sizeof(struct compat_msqid64_ds) != 104);
542 	BUILD_BUG_ON(sizeof(struct compat_shmid64_ds) != 104);
543 #endif
544 
545 	/* Do sanity checks on page table constants */
546 	BUILD_BUG_ON(PTE_ENTRY_SIZE != sizeof(pte_t));
547 	BUILD_BUG_ON(PMD_ENTRY_SIZE != sizeof(pmd_t));
548 	BUILD_BUG_ON(PGD_ENTRY_SIZE != sizeof(pgd_t));
549 	BUILD_BUG_ON(PAGE_SHIFT + BITS_PER_PTE + BITS_PER_PMD + BITS_PER_PGD
550 			> BITS_PER_LONG);
551 #if CONFIG_PGTABLE_LEVELS == 3
552 	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PMD);
553 #else
554 	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PGD);
555 #endif
556 
557 #ifdef CONFIG_64BIT
558 	/* avoid ldil_%L() asm statements to sign-extend into upper 32-bits */
559 	BUILD_BUG_ON(__PAGE_OFFSET >= 0x80000000);
560 	BUILD_BUG_ON(TMPALIAS_MAP_START >= 0x80000000);
561 #endif
562 
563 	high_memory = __va((max_pfn << PAGE_SHIFT));
564 	set_max_mapnr(max_low_pfn);
565 	memblock_free_all();
566 
567 #ifdef CONFIG_PA11
568 	if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) {
569 		pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
570 		parisc_vmalloc_start = SET_MAP_OFFSET(pcxl_dma_start
571 						+ PCXL_DMA_MAP_SIZE);
572 	} else
573 #endif
574 		parisc_vmalloc_start = SET_MAP_OFFSET(MAP_START);
575 
576 #if 0
577 	/*
578 	 * Do not expose the virtual kernel memory layout to userspace.
579 	 * But keep code for debugging purposes.
580 	 */
581 	printk("virtual kernel memory layout:\n"
582 	       "     vmalloc : 0x%px - 0x%px   (%4ld MB)\n"
583 	       "     fixmap  : 0x%px - 0x%px   (%4ld kB)\n"
584 	       "     memory  : 0x%px - 0x%px   (%4ld MB)\n"
585 	       "       .init : 0x%px - 0x%px   (%4ld kB)\n"
586 	       "       .data : 0x%px - 0x%px   (%4ld kB)\n"
587 	       "       .text : 0x%px - 0x%px   (%4ld kB)\n",
588 
589 	       (void*)VMALLOC_START, (void*)VMALLOC_END,
590 	       (VMALLOC_END - VMALLOC_START) >> 20,
591 
592 	       (void *)FIXMAP_START, (void *)(FIXMAP_START + FIXMAP_SIZE),
593 	       (unsigned long)(FIXMAP_SIZE / 1024),
594 
595 	       __va(0), high_memory,
596 	       ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
597 
598 	       __init_begin, __init_end,
599 	       ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10,
600 
601 	       _etext, _edata,
602 	       ((unsigned long)_edata - (unsigned long)_etext) >> 10,
603 
604 	       _text, _etext,
605 	       ((unsigned long)_etext - (unsigned long)_text) >> 10);
606 #endif
607 }
608 
609 unsigned long *empty_zero_page __ro_after_init;
610 EXPORT_SYMBOL(empty_zero_page);
611 
612 /*
613  * pagetable_init() sets up the page tables
614  *
615  * Note that gateway_init() places the Linux gateway page at page 0.
616  * Since gateway pages cannot be dereferenced this has the desirable
617  * side effect of trapping those pesky NULL-reference errors in the
618  * kernel.
619  */
620 static void __init pagetable_init(void)
621 {
622 	int range;
623 
624 	/* Map each physical memory range to its kernel vaddr */
625 
626 	for (range = 0; range < npmem_ranges; range++) {
627 		unsigned long start_paddr;
628 		unsigned long size;
629 
630 		start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT;
631 		size = pmem_ranges[range].pages << PAGE_SHIFT;
632 
633 		map_pages((unsigned long)__va(start_paddr), start_paddr,
634 			  size, PAGE_KERNEL, 0);
635 	}
636 
637 #ifdef CONFIG_BLK_DEV_INITRD
638 	if (initrd_end && initrd_end > mem_limit) {
639 		printk(KERN_INFO "initrd: mapping %08lx-%08lx\n", initrd_start, initrd_end);
640 		map_pages(initrd_start, __pa(initrd_start),
641 			  initrd_end - initrd_start, PAGE_KERNEL, 0);
642 	}
643 #endif
644 
645 	empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
646 	if (!empty_zero_page)
647 		panic("zero page allocation failed.\n");
648 
649 }
650 
651 static void __init gateway_init(void)
652 {
653 	unsigned long linux_gateway_page_addr;
654 	/* FIXME: This is 'const' in order to trick the compiler
655 	   into not treating it as DP-relative data. */
656 	extern void * const linux_gateway_page;
657 
658 	linux_gateway_page_addr = LINUX_GATEWAY_ADDR & PAGE_MASK;
659 
660 	/*
661 	 * Setup Linux Gateway page.
662 	 *
663 	 * The Linux gateway page will reside in kernel space (on virtual
664 	 * page 0), so it doesn't need to be aliased into user space.
665 	 */
666 
667 	map_pages(linux_gateway_page_addr, __pa(&linux_gateway_page),
668 		  PAGE_SIZE, PAGE_GATEWAY, 1);
669 }
670 
671 static void __init fixmap_init(void)
672 {
673 	unsigned long addr = FIXMAP_START;
674 	unsigned long end = FIXMAP_START + FIXMAP_SIZE;
675 	pgd_t *pgd = pgd_offset_k(addr);
676 	p4d_t *p4d = p4d_offset(pgd, addr);
677 	pud_t *pud = pud_offset(p4d, addr);
678 	pmd_t *pmd;
679 
680 	BUILD_BUG_ON(FIXMAP_SIZE > PMD_SIZE);
681 
682 #if CONFIG_PGTABLE_LEVELS == 3
683 	if (pud_none(*pud)) {
684 		pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER,
685 				     PAGE_SIZE << PMD_TABLE_ORDER);
686 		if (!pmd)
687 			panic("fixmap: pmd allocation failed.\n");
688 		pud_populate(NULL, pud, pmd);
689 	}
690 #endif
691 
692 	pmd = pmd_offset(pud, addr);
693 	do {
694 		pte_t *pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
695 		if (!pte)
696 			panic("fixmap: pte allocation failed.\n");
697 
698 		pmd_populate_kernel(&init_mm, pmd, pte);
699 
700 		addr += PAGE_SIZE;
701 	} while (addr < end);
702 }
703 
704 static void __init parisc_bootmem_free(void)
705 {
706 	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, };
707 
708 	max_zone_pfn[0] = memblock_end_of_DRAM();
709 
710 	free_area_init(max_zone_pfn);
711 }
712 
713 void __init paging_init(void)
714 {
715 	setup_bootmem();
716 	pagetable_init();
717 	gateway_init();
718 	fixmap_init();
719 	flush_cache_all_local(); /* start with known state */
720 	flush_tlb_all_local(NULL);
721 
722 	sparse_init();
723 	parisc_bootmem_free();
724 }
725 
726 static void alloc_btlb(unsigned long start, unsigned long end, int *slot,
727 			unsigned long entry_info)
728 {
729 	const int slot_max = btlb_info.fixed_range_info.num_comb;
730 	int min_num_pages = btlb_info.min_size;
731 	unsigned long size;
732 
733 	/* map at minimum 4 pages */
734 	if (min_num_pages < 4)
735 		min_num_pages = 4;
736 
737 	size = HUGEPAGE_SIZE;
738 	while (start < end && *slot < slot_max && size >= PAGE_SIZE) {
739 		/* starting address must have same alignment as size! */
740 		/* if correctly aligned and fits in double size, increase */
741 		if (((start & (2 * size - 1)) == 0) &&
742 		    (end - start) >= (2 * size)) {
743 			size <<= 1;
744 			continue;
745 		}
746 		/* if current size alignment is too big, try smaller size */
747 		if ((start & (size - 1)) != 0) {
748 			size >>= 1;
749 			continue;
750 		}
751 		if ((end - start) >= size) {
752 			if ((size >> PAGE_SHIFT) >= min_num_pages)
753 				pdc_btlb_insert(start >> PAGE_SHIFT, __pa(start) >> PAGE_SHIFT,
754 					size >> PAGE_SHIFT, entry_info, *slot);
755 			(*slot)++;
756 			start += size;
757 			continue;
758 		}
759 		size /= 2;
760 		continue;
761 	}
762 }
763 
764 void btlb_init_per_cpu(void)
765 {
766 	unsigned long s, t, e;
767 	int slot;
768 
769 	/* BTLBs are not available on 64-bit CPUs */
770 	if (IS_ENABLED(CONFIG_PA20))
771 		return;
772 	else if (pdc_btlb_info(&btlb_info) < 0) {
773 		memset(&btlb_info, 0, sizeof btlb_info);
774 	}
775 
776 	/* insert BLTLBs for code and data segments */
777 	s = (uintptr_t) dereference_function_descriptor(&_stext);
778 	e = (uintptr_t) dereference_function_descriptor(&_etext);
779 	t = (uintptr_t) dereference_function_descriptor(&_sdata);
780 	BUG_ON(t != e);
781 
782 	/* code segments */
783 	slot = 0;
784 	alloc_btlb(s, e, &slot, 0x13800000);
785 
786 	/* sanity check */
787 	t = (uintptr_t) dereference_function_descriptor(&_edata);
788 	e = (uintptr_t) dereference_function_descriptor(&__bss_start);
789 	BUG_ON(t != e);
790 
791 	/* data segments */
792 	s = (uintptr_t) dereference_function_descriptor(&_sdata);
793 	e = (uintptr_t) dereference_function_descriptor(&__bss_stop);
794 	alloc_btlb(s, e, &slot, 0x11800000);
795 }
796 
797 #ifdef CONFIG_PA20
798 
799 /*
800  * Currently, all PA20 chips have 18 bit protection IDs, which is the
801  * limiting factor (space ids are 32 bits).
802  */
803 
804 #define NR_SPACE_IDS 262144
805 
806 #else
807 
808 /*
809  * Currently we have a one-to-one relationship between space IDs and
810  * protection IDs. Older parisc chips (PCXS, PCXT, PCXL, PCXL2) only
811  * support 15 bit protection IDs, so that is the limiting factor.
812  * PCXT' has 18 bit protection IDs, but only 16 bit spaceids, so it's
813  * probably not worth the effort for a special case here.
814  */
815 
816 #define NR_SPACE_IDS 32768
817 
818 #endif  /* !CONFIG_PA20 */
819 
820 #define RECYCLE_THRESHOLD (NR_SPACE_IDS / 2)
821 #define SID_ARRAY_SIZE  (NR_SPACE_IDS / (8 * sizeof(long)))
822 
823 static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
824 static unsigned long dirty_space_id[SID_ARRAY_SIZE];
825 static unsigned long space_id_index;
826 static unsigned long free_space_ids = NR_SPACE_IDS - 1;
827 static unsigned long dirty_space_ids;
828 
829 static DEFINE_SPINLOCK(sid_lock);
830 
831 unsigned long alloc_sid(void)
832 {
833 	unsigned long index;
834 
835 	spin_lock(&sid_lock);
836 
837 	if (free_space_ids == 0) {
838 		if (dirty_space_ids != 0) {
839 			spin_unlock(&sid_lock);
840 			flush_tlb_all(); /* flush_tlb_all() calls recycle_sids() */
841 			spin_lock(&sid_lock);
842 		}
843 		BUG_ON(free_space_ids == 0);
844 	}
845 
846 	free_space_ids--;
847 
848 	index = find_next_zero_bit(space_id, NR_SPACE_IDS, space_id_index);
849 	space_id[BIT_WORD(index)] |= BIT_MASK(index);
850 	space_id_index = index;
851 
852 	spin_unlock(&sid_lock);
853 
854 	return index << SPACEID_SHIFT;
855 }
856 
857 void free_sid(unsigned long spaceid)
858 {
859 	unsigned long index = spaceid >> SPACEID_SHIFT;
860 	unsigned long *dirty_space_offset, mask;
861 
862 	dirty_space_offset = &dirty_space_id[BIT_WORD(index)];
863 	mask = BIT_MASK(index);
864 
865 	spin_lock(&sid_lock);
866 
867 	BUG_ON(*dirty_space_offset & mask); /* attempt to free space id twice */
868 
869 	*dirty_space_offset |= mask;
870 	dirty_space_ids++;
871 
872 	spin_unlock(&sid_lock);
873 }
874 
875 
876 #ifdef CONFIG_SMP
877 static void get_dirty_sids(unsigned long *ndirtyptr,unsigned long *dirty_array)
878 {
879 	int i;
880 
881 	/* NOTE: sid_lock must be held upon entry */
882 
883 	*ndirtyptr = dirty_space_ids;
884 	if (dirty_space_ids != 0) {
885 	    for (i = 0; i < SID_ARRAY_SIZE; i++) {
886 		dirty_array[i] = dirty_space_id[i];
887 		dirty_space_id[i] = 0;
888 	    }
889 	    dirty_space_ids = 0;
890 	}
891 
892 	return;
893 }
894 
895 static void recycle_sids(unsigned long ndirty,unsigned long *dirty_array)
896 {
897 	int i;
898 
899 	/* NOTE: sid_lock must be held upon entry */
900 
901 	if (ndirty != 0) {
902 		for (i = 0; i < SID_ARRAY_SIZE; i++) {
903 			space_id[i] ^= dirty_array[i];
904 		}
905 
906 		free_space_ids += ndirty;
907 		space_id_index = 0;
908 	}
909 }
910 
911 #else /* CONFIG_SMP */
912 
913 static void recycle_sids(void)
914 {
915 	int i;
916 
917 	/* NOTE: sid_lock must be held upon entry */
918 
919 	if (dirty_space_ids != 0) {
920 		for (i = 0; i < SID_ARRAY_SIZE; i++) {
921 			space_id[i] ^= dirty_space_id[i];
922 			dirty_space_id[i] = 0;
923 		}
924 
925 		free_space_ids += dirty_space_ids;
926 		dirty_space_ids = 0;
927 		space_id_index = 0;
928 	}
929 }
930 #endif
931 
932 /*
933  * flush_tlb_all() calls recycle_sids(), since whenever the entire tlb is
934  * purged, we can safely reuse the space ids that were released but
935  * not flushed from the tlb.
936  */
937 
938 #ifdef CONFIG_SMP
939 
940 static unsigned long recycle_ndirty;
941 static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
942 static unsigned int recycle_inuse;
943 
944 void flush_tlb_all(void)
945 {
946 	int do_recycle;
947 
948 	do_recycle = 0;
949 	spin_lock(&sid_lock);
950 	__inc_irq_stat(irq_tlb_count);
951 	if (dirty_space_ids > RECYCLE_THRESHOLD) {
952 	    BUG_ON(recycle_inuse);  /* FIXME: Use a semaphore/wait queue here */
953 	    get_dirty_sids(&recycle_ndirty,recycle_dirty_array);
954 	    recycle_inuse++;
955 	    do_recycle++;
956 	}
957 	spin_unlock(&sid_lock);
958 	on_each_cpu(flush_tlb_all_local, NULL, 1);
959 	if (do_recycle) {
960 	    spin_lock(&sid_lock);
961 	    recycle_sids(recycle_ndirty,recycle_dirty_array);
962 	    recycle_inuse = 0;
963 	    spin_unlock(&sid_lock);
964 	}
965 }
966 #else
967 void flush_tlb_all(void)
968 {
969 	spin_lock(&sid_lock);
970 	__inc_irq_stat(irq_tlb_count);
971 	flush_tlb_all_local(NULL);
972 	recycle_sids();
973 	spin_unlock(&sid_lock);
974 }
975 #endif
976 
977 static const pgprot_t protection_map[16] = {
978 	[VM_NONE]					= PAGE_NONE,
979 	[VM_READ]					= PAGE_READONLY,
980 	[VM_WRITE]					= PAGE_NONE,
981 	[VM_WRITE | VM_READ]				= PAGE_READONLY,
982 	[VM_EXEC]					= PAGE_EXECREAD,
983 	[VM_EXEC | VM_READ]				= PAGE_EXECREAD,
984 	[VM_EXEC | VM_WRITE]				= PAGE_EXECREAD,
985 	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_EXECREAD,
986 	[VM_SHARED]					= PAGE_NONE,
987 	[VM_SHARED | VM_READ]				= PAGE_READONLY,
988 	[VM_SHARED | VM_WRITE]				= PAGE_WRITEONLY,
989 	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
990 	[VM_SHARED | VM_EXEC]				= PAGE_EXECREAD,
991 	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_EXECREAD,
992 	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_RWX,
993 	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_RWX
994 };
995 DECLARE_VM_GET_PAGE_PROT
996 
997 #ifdef CONFIG_EXECMEM
998 static struct execmem_info execmem_info __ro_after_init;
999 
1000 struct execmem_info __init *execmem_arch_setup(void)
1001 {
1002 	execmem_info = (struct execmem_info){
1003 		.ranges = {
1004 			[EXECMEM_DEFAULT] = {
1005 				.start	= VMALLOC_START,
1006 				.end	= VMALLOC_END,
1007 				.pgprot	= PAGE_KERNEL_RWX,
1008 				.alignment = 1,
1009 			},
1010 		},
1011 	};
1012 
1013 	return &execmem_info;
1014 }
1015 #endif /* CONFIG_EXECMEM */
1016